Insecticide



Patented Oct. 5, 1937 UNITED STATES PATENT OFFICE INSEGTICIDE of America No Drawing. Application June 27, 1936, Serial No. 87,743

6 Claims.

(Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 157) This application is made under the act of March 3, 1883, as amended by the act of April 30, 1928, and the invention herein described, if patented, may be manufactured and used by or for the Government for governmental purposes without the payment to us of any royalty thereon.

We hereby dedicate the invention herein described to the free use of the Public in the territory of the United States of America to take effect upon the granting of a patent to us.

This invention relates to improvements in materials for destroying or checking the growth or multiplication of living organisms, whether plant or animal, which are economically injurious to man.

An object of the invention is to provide materials suitable for use as insecticides.

Another object of the invention is to provide a material for dusting or spraying delicate vegetation such as bean plants, peach trees, and plants grown under glass, which will not cause injury to foliage.

Another object of the invention is to provide a material which is relatively non-toxic to man and domestic animals when taken by mouth, and which can be used in place of lead arsenate and other arsenicals for destroying insects without leaving harmful residues on fruits and vegetables.

We have found that substances belonging to a certain class of organic compounds have a specific toxic effect upon harmful insects, and our invention consists in the application of said substances to the destruction of insect pests,

The novel insecticides found by us belong to v the class of organic compounds which contain in their molecules, according to accepted formulation, two homocyclic nuclei joined by an azo linkage, that is, by-the N=N- group and which contain, in addition to at least one hydroxyl group, and one or more nitro groups, one or more substituents chosen from the list comprising halogen, aryl, alkyl, and aralkyl groups, and hydrogen.

Typical representatives of this class of compounds are:

p'(p-nitrophenylazo)-phenol 4-(p-nitrophenylazo)-resorclnol i-(i-chloro-z-nitrophenylazo)-o-cresol No. on.

4-(pbromophenylazo)-2-nitrophenol p-(2,4-dinitrophenylazo)-phenol But these examples are representative only and are not intended to comprise all the compounds which fall under the definition of the paragraph immediately above.

For specific examples of the toxicity of these compounds it may be mentioned that when 4- (p-nitrophenylazo) -resorcinol was dissolved in acetone and the resulting solution poured into water there resulted a mortality of more than 50% of culicine mosquito larvae within 16 hours when the concentration of the azo compound was one part to 300,000 parts of water.

When l-(p-nitrophenylazo)-2-naphthol was dissolved in acetone and the resulting solution poured into water there resulted a mortality of more than 90% of culicine mosquito larvae within 16 hours when the concentration of the azo compound was one part to 25,000 parts of water.

The above examples are not to be construed as limiting either the method of application of these novel insecticides or the kinds of insects to which they may be applied.

These azo compounds may be applied in a manner similar to that in which insecticides in general are used, that is, as dusts, or in the form of solutions or suspensions in various media, such as water, kerosene, etc., and either with or without the use of spreaders, wetting agents, or sticking agents.

Having thus described our invention we claim:

1. As insecticides hydroxy azo compounds containing at least one hydroxy group and at least one nitro group.

2. As insecticides hydroxy azo compounds containing at least one hydroxy group and at least one nitro group, together with at least one halogen atom.

3. As insecticides hydroxy azo compounds containing at least one hydroxy group and at least 5. An insecticide containing as its essential active ingredient 4- (p-nitrophenylazo) -resorcinol. 6. An insecticide containing as its essential active ingredient l-(p-nitrophenylazo)-2-naphtho].

DONALD L. VIVIAN. HERBERT L. J. HALLER. 

